This prompt continues to afflict me after a week or so of trying to get the market freebies. b
I had this too, but turns out to be an issue with Low Poly Style Deluxe 2: Tropical Environment. Remove it from your cart and you should be good.
I appreciate the response removed it. It didn’t go through. i suppose i’ll try removing one at a time till it goes through.
There seems to be an issue with the Old West packs, specifically Vol 3, 4, and 6.
When a combination of one of those and another pack is present in the cart, the message mentioned by OP is displayed. But if only one of them is added, the message “Sorry, you already own this item, or it’s still being processed.” is shown.
Unfortunately, I haven’t found a solution as of yet.